title: Avian synaptopodin 2 (fesselin) stabilizes myosin filaments and actomyosin in the presence of ATP.
abstract: Smooth muscle cells maintain filaments of actin and myosin in the presence of ATP, although dephosphorylated myosin filaments and actin-myosin interactions are unstable under those conditions in vitro. Several proteins that stabilize myosin filaments and that stabilize actin-myosin interactions have been identified. Fesselin or synaptopodin 2 appears to be another such protein. Rapid kinetic measurements and electron microscopy demonstrated that fesselin, isolated from turkey gizzard muscle, reduced the rate of dissociation of myosin filaments. Addition of fesselin increased both the length and thickness of myosin filaments. The rate of detachment of myosin, but not heavy meromyosin, from actin was also greatly reduced by fesselin. Data from this study suggest that fesselin stabilizes myosin filaments and tethers myosin to actin. These results support the view that one role of fesselin is to organize contractile units of myosin and actin.
authors.affiliation: Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University , 600 Moye Boulevard, Greenville, North Carolina 27834-4300, United States.
authors.forename: Nathanial L
authors.initials: NL
authors.lastname: Kingsbury
authors.forename: Randall H
authors.initials: RH
authors.lastname: Renegar
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Chalovich
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D000205:Actomyosin / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D030161:Avian Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D003599:Cytoskeleton / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D005895:Gizzard, Avian; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D008840:Microfilament Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009130:Muscle, Smooth / Q000378:metabolism; D015879:Myosin Subfragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D055550:Protein Stability; D011817:Rabbits; D022142:Secretory Vesicles / Q000378:metabolism / Q000648:ultrastructure; D024745:Smooth Muscle Myosins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D014422:Turkeys
chemical_list: D000199:Actins; D030161:Avian Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D015879:Myosin Subfragments; C443099:fesselin; D000255:Adenosine Triphosphate; D000205:Actomyosin; D024745:Smooth Muscle Myosins